Mounting means for infra-red transmitters and receivers



July 23, 1963 J. K. STEWART 3,098,302

MOUNTING MEANS FOR INFRA-RED TRANSMITTERS AND RECEIVERS INVENTOR JOHN K. STEWART BY ATTORNEYS.

2 Sheets-Sheet 1 Filed June 50, 1961 July 23, 1963 J. K. STEWART 3,093,302

MOUNTING MEANS FOR INFRA-RED TRANSMITTERS AND RECEIVERS Filed June 30, 1961 2 Sheets-Sheet 2 INVENTOR JOHN K. STEWART ATTORNEYS.

United States Patent 3,098,302 MOUNTING MEANS FOR INFRA-RED TRANSMHTERS AND RECEIVERS John Kenneth Stewart, Dorval, Quebec, Canada, assignor t) Cagada Iron Foundries, Limited, Montreal, Quebec,

ana 2 Filed June 30, 1961, Ser. No. 121,079 7 Claims. (Cl. 33-46) This invention relates to railroad track surveying devices of the type which use high frequency beam transmitters on a remote carriage, a high frequency beam receiver on a second or base carriage, usually a tamping machine, and a shadow board adjacent the tamping machine to interfere with the transmitted beam. Such a system is described in my Canadian Patent No. 650,557, issued Oct. 16, 1962.

One of the drawbacks of earlier devices has been that when the transmitters on the remote, or first, carriage on the railway track has moved out of alignment with the receiver on the second carriage by reason that the first carriage having entered a curve on the track, the beamed signal from the transmitters has been difiicult to obtain. This difficulty maintains throughout the curve, and increased with the sharpness of the curve.

It is an object of the present invention to provide means whereby the transmitters and receivers may be maintained in substantial alignment whilst negotiating normal railroad track curves.

Accordingly, the present invention provides in a railroad track surveying device, a first carriage adapted for movement on a railroad track, high frequency beam transmitter means pivotally mounted on said first carriage; a second carriage adapted for movement on the railroad track and normally spaced from said first carriage; high frequency beam receiver means pivotally mounted on said second carriage and adapted to receive the transmitter beam from said transmitter means; and linkage means between said transmitter means and said receiver means adapted to maintain the transmitter means and the receiver means in substantial alignment with respect to each other.

Preferably, the high frequency beam is an infra-red light beam.

According to a preferred construction a pair of infrared beam transmitters are pivotally mounted to the first carriage and a pair of infra-red light beam receivers are pivotally mounted to the second carriage.

The following is a description by way of example of one embodiment of the present invention reference being had to the accompanying drawings in which:

FIGURE 1 is a schematic plan view of the device, not a scale, of two carriages on a curve on a railroad track.

FIGURES 2 and 3 are details; and,

FIGURES 4a and 4b together provide a pictorial representation of the mounting of the present device on a front carriage and its mounting of on a second carriage.

Referring now to the drawings. A first carriage 10 is mounted on rail engaging wheels so that it is capable of movement on a railroad track 11. The carriage 10' may carry its own prime mover or may be driven by electric motor from a power source on the second carriage 12 which is similarly mounted on rail engaging wheels for movement on track 11. Under normal surveying condi tions the second carriage 12 would be a tamping machine and probably also equipped with jacks and a shadow board would be provided in engagement of the track 11 and in front of, and adjacent to, the carriage 12.

The first carriage has a pair of infra-red light beam transmitters 1 and '16 pivotally mounted thereon and the carriage 12 has a pair of infra-red light beam receivers 17 and .18 pivotally mounted thereon. These light beam receivers are normally of the photoelectric cell variety. The

connecting linkage generally indicated at 20 extends between the transmitters and receivers and operates to keep them in substantial alignment with respect to each other even when the front carriage has moved into a curve in the track and thus out longitudinal alignment with the carriage .12.

FIGURES 4a and 4b illustrate the linkage .20 in detail. The carriage 10* has a structure 10s to which the transmitters 1'5 and 16 are mounted on pivoted pins 25, 26 substantially above each rail of the track and arranged to project an infra-red light beam back along the track in the general direction of the second car 12. A pair of crank arms 27, .28 extend outwardly away from the pivot pins 2-5, 26 and are attached to the pivot pins 25, 26.

The crank arms .27, 28 are connected by a connecting link 30 which is pivoted at 30a and 30b to the crank arms 27, 28. The connecting arm 30' is provided with a centrally located bushing 31.

The second carriage has a frame 12s to which the receivers -17 and 18 are pivotally mounted on similar pivot pins 34, 35 to which are attached a pair of crank arms 36, 3'7 pivotally connected at their outer extremities to connecting link means generally indicated at 40. The connecting link means comprises the guide channel member 41 mounted on a pivot pin 42 on the frame 12s, and eX- tending in the general direction of the first carriage, wing arms 4-3, 44 on either side of the guide channel member 4-1 pivotally connected at their outer extremities to a pair of intermediate links 45, 46. The links 45, 46 pivotally connect the wing arms 43, 44 and the crank arms 36, 37.

A cable reel 50 is mounted on the second carriage 12 and the cable 51 therefrom passes up and over a pulley 41p in the guide channel 41. The cable 51 spans the distance between the first and second carriages and engages a bushing 31 on the connecting link 30. The cable passes through the bushing and around a series of sheaves 5'5, 56 to an anchoring point 57 on the front carriage 10. The sheaves 55 and '56 are provided with a spring loaded counterbalance means generally indicated at 58.

In operation when the first carriage enters a curve before the second carriage, or, as in the condition shown in FIGURE 1, when both are in the curve, the cable 51 or other flexible link, tries to keep a straight line between the first and second carriages and as a consequence bears against the side of the bushing 31 and the guide channel 41 to pivot the transmitter and receivers on their pivot pins 25, 26, 34-, 35 so that the transmitters and receivers will be in substantial alignment as indicated by the dotted lines 60 and 61 in FIGURE 1.

The cable 51 may, if desired, comprise an electrical energy conductor cable for the greatest part of this span, that is to say, it could be an electrical cable 51a to the point 51b (FIGURE 4b) and thereafter a steel cable 51c mechanically connected to the cable 51a, the cables 51:, 51c together form the cable means connecting the two carriages together. The free end of cable 5111 can, under these circumstances be used to connect an electrical source of energy to a driving motor on the carriage 10.

However, the first carriage could, if desired, have a selfcontained driving unit in which case the cable means 51a, 510 could be a simple steel cable from beginning to end.

It will be clear that it is not essential to keep the transmitters and receivers in absolute alignment with each other since there is bound to be a certain amount of spread of the transmitter beam and provided that the transmitters and receivers are kept sufiiciently in alignment as to be within the spread of this light beam span then the device will function effectively.

What is claimed as my invention is:

1. In a railroad track surveying device, a first carriage adapted for movement in a railroad track, high frequency beam transmitter means pivotally mounted on said first carriage; a second carriage adapted for movement on the railroad track and normally spaced from said first car riage; high frequency beam receiver means pivotally mounted on said second carriage and adapted to receive the transmitter beam from said transmitter means; and linkage means between said transmitter means and said receiver means adapted to maintain the transmitter means wd the receiver means in substantial alignment with respect to each other, said linkage means including a flexible link substantially spanning the distance between the carriages.

2. In a railroad track surveying device, a first carriage adapted for movement on a railroad track, a pair of infrared beam transmitters pivotally mounted on said carriage one substantially above each rail of the track; a second carriage adapted for movement on the railroad track and normally spaced from said first carriage; a pair of infrared light beam receivers pivotally mounted on said second carriage one substantially above the each rail of the track and adapted to receive the transmitted infra-red light from said transmitters; and linkage means between said transmitters and said receivers adapted to maintain the transmitters and receivers in substantial alignment, said linkage means including a flexible link substantially spanning the distancebetween the carriages.

3. A device as claimed in claim 2 in which the linkage means comprises a crank arm operatively connected to each transmitter; a connecting link operatively connected between the crank arm; a crank arm operatively connected to each receiver, connecting link means between these 4 crank arms; and a flexible connecting link engaging said connecting link and said connecting link means and spaning the distance there'between.

4. A device as claimed in claim 3 in which the connecting link means comprises a guide channel substantially centrally located on the said second carriage between the receivers, pivotally connected to said second carriage and extending normally in a direction towards said second carriage; said guide channel being adapted to pass said flexible connecting link; a pair of wing arms on the sides of the guide channel and extending outwardly therefrom; and a pair of intermediate links operatively connecting each wing arm with its associated receiver crank arm.

5. A device as claimed in claim 4 in which the flexible link is a cable means mounted to a reel on the said second carriage and the guide channel includes a pulley to pass said cable.

6. A device as claimed in claim 4 in which the cable means engages the connecting link centrally thereof through a bushing thereon and is anchored to the said first carriage.

7. A device as claimed in claim 6 in which said cable means is connected to a spring counterbalance means on said first carriage.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A RAILROAD TRACK SURVEYING DEVICE, A FIRST CARRIAGE ADAPTED FOR MOVEMENT IN A RAILROAD TRACK, HIGH FREQUENCY BEAM TRANSMITTED MEANS PIVOTALLY MOUNTED ON SAID FIRST CARRIAGE; A SECOND CARRIAGE ADAPTED FOR MOVEMENT ON THE RAILROAD TRACK AND NORMALLY SPACED FROM SAID FIRST CARRIAGE; HIGH FREQUENCY BEAM RECEIVER MEANS PIVOTALLY MOUNTED ON SAID SECOND CARRIAGE AND ADAPTED TO RECEIVE THE TRANSMITTER BEAM FROM SAID TRANSMITTER MEANS; AND LINKAGE MEANS BETWEEN SAID TRANSMITTER MEANS AND SAID RECEIVER MEANS ADAPTED TO MAINTAIN THE TRANSMITTER MEANS AND THE RECEIVER MEANS IN SUBSTANTIAL ALIGNMENT WITH RESPECT TO EACH OTHER, SAID LINKAGE MEANS INCLUDING A FLEXIBLE LINK SUBSTANTIALLY SPANNING THE DISTANCE BETWEEN THE CARRIAGES. 